Messages in this thread | | | Subject | Re: [PATCH 3/3] mm: oom: show unreclaimable slab info when kernel panic | From | Tetsuo Handa <> | Date | Fri, 15 Sep 2017 21:00:43 +0900 |
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On 2017/09/15 2:14, Yang Shi wrote: > @@ -1274,6 +1276,29 @@ static int slab_show(struct seq_file *m, void *p) > return 0; > } > > +void show_unreclaimable_slab() > +{ > + struct kmem_cache *s = NULL; > + struct slabinfo sinfo; > + > + memset(&sinfo, 0, sizeof(sinfo)); > + > + printk("Unreclaimable slabs:\n"); > + mutex_lock(&slab_mutex);
Please avoid sleeping locks which potentially depend on memory allocation. There are
mutex_lock(&slab_mutex); kmalloc(GFP_KERNEL); mutex_unlock(&slab_mutex);
users which will fail to call panic() if they hit this path.
> + list_for_each_entry(s, &slab_caches, list) { > + if (!is_root_cache(s)) > + continue; > + > + get_slabinfo(s, &sinfo); > + > + if (!is_reclaimable(s) && sinfo.num_objs > 0) > + printk("%-17s %luKB\n", cache_name(s), K(sinfo.num_objs * s->size)); > + } > + mutex_unlock(&slab_mutex); > +} > +EXPORT_SYMBOL(show_unreclaimable_slab); > +#undef K > + > #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) > void *memcg_slab_start(struct seq_file *m, loff_t *pos) > { >
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